【2011山东菏泽】34.—Will you stay for some more days?
—Sorry,I_____.My mother called to ask me to go back at once.
A.mustn’t B.may not C.can’t D.wouldn’t
答案：C
【解析】情态动词表推测.句意：－你再呆几天好吗?－对不起,我不能,我的母亲打电话让我马上回去.Mustn’t禁止；may not可能不；wouldn’t不愿做……,将要不…….故选C.